This invention relates generally to mowing equipment and more particularly to a flexible line trimmer which may be attached to and used with a tractor driven mower deck to provide close trimming around trees and other obstructions.
The mowing of fields and other large tracts of land, including many lawns, is often carried out by using a tractor driven mowing deck. Although this type of equipment provides a wide mowing swath and thus covers large areas well, it is unable to trim closely around trees and other obstacles such as fence posts or bushes. Accordingly, hand held flexible line trimmers and other types of trimming devices are usually used separately for trimming around trees and the like. This can significantly increase the time and labor required to complete the job, especially in heavily treed areas or other areas having a large number of objects that require close trimming.
The present invention is directed to a flexible line trimmer attachment which operates to trim closely around trees and other obstacles at the same time as the mower deck is used for mowing. It is a particular object of the invention to provide a trimmer attachment which may be used with various makes and models of mowing decks and which neatly trims around obstacles without requiring precise maneuvering of the tractor. Another important object of the invention is to provide a trimmer attachment that may be provided either as original equipment attached to the mowing deck when it is sold or as an attachment that may be connected with an existing mowing deck. Another significant feature of the invention is the simplicity of the structure of the trimmer attachment and its ability to make use of the power system for the tractor of the mowing deck.
In accordance with the invention, a horizontal boom is pivotally attached at one end to the mowing deck of a tractor driven mower. The boom extends laterally to one side of the deck and can deflect about its pivot connection when it encounters an obstacle such as a tree. A return spring is provided to pivot the boom back to its normal laterally extending position as soon as the obstacle has been cleared.
A pair of trimming heads are carried on the boom. Each trimming head is equipped with a flexible trimming line that is driven by the trimming head in order to trim around trees and other objects when the trimming heads are driven by hydraulic or electric motors or another drive mechanism. An adjustable shoe on the bottom of one of the trimming heads controls the trimming height.
As the boom approaches an obstacle such as a tree, the trimming heads are able to trim right up to the tree. As the boom deflects pivotally when the tree is encountered, the trimming heads are able to trim along its side and even partially along the back side of the tree as the boom is clearing the tree and the return spring pivots the boom back to its lateral position. The pivotal mounting arrangement and return spring are thus important features of the invention which permit close trimming without the need for precise steering of the tractor or other tractor maneuvering that might interfere with the mowing function.
Another important feature of the invention is the construction of the boom in two sections which are hinged together. This permits the outboard boom section which carries the trimming heads to "float" up and down about the hinge axis when uneven terrain is being traversed, and it allows inclined areas to be trimmed evenly because the outboard boom section is automatically maintained parallel to the slope even if the tractor is on more horizontal terrain. The hinge construction of the boom also allows the outboard boom section to be raised to a storage position when the mowing deck is used without need for trimming or when the machine is being stored and a reduced width is desirable.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.